Abstract

We describe the design and the early results of a feasibility experiment for sodium-layer laser-guide-star adaptive optics. Copper-vapor-laser-pumped dye lasers from Lawrence Livermore National Laboratory’s Atomic Vapor Laser Isotope Separation program are used to create the guide star. The laser beam is projected upward from a beam director that is located ~5 m from a 0.5-m telescope and forms an irradiance spot ~2 m in diameter at the atmospheric-sodium layer (at an altitude of 95 km). The laser guide star is approximately fifth magnitude and is visible to the naked eye at the top of the Rayleigh-scattered laser beam. To date, we have made photometric measurements and open-loop wave-front-sensor measurements of the laser guide star. We give an overview of the experiment’s design and the laser systems, describe the experimental setup, show preliminary photometric and open-loop wave-front-sensor data on the guide star, and present predictions of closed-loop adaptive-optics performance based on these experimental data. The long-term goal of this effort is to develop laser guide stars and adaptive optics for use with large astronomical telescopes.

© 1994 Optical Society of America

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  1. W. Happer, G. MacDonald, C. Max, F. Dyson, “Atmospheric-turbulence compensation by resonant optical backscattering from the sodium layer in the upper atmosphere,” J. Opt. Soc. Am. A 11, 263–276 (1994).
    [Crossref]
  2. R. Foy, A. Labeyrie, “Feasibility of adaptive optics telescope with laser probe,” Astron. Astrophys. 152, L29–L31 (1985); L. A. Thompson, C. S. Gardner, “Experiments on laser guide stars at Mauna Kea Observatory for adaptive imaging in astronomy,” Nature (London) 328, 229–231 (1987); R. A. Humphries, C. Primmerman, L. Bradley, J. Hermann, “Atmospheric turbulence measurements using a synthetic beacon in the mesospheric sodium layer,” Opt. Lett. 16, 1367–1369 (1991).
    [Crossref]
  3. R. Q. Fugate, D. Fried, G. Ameer, B. Boeke, S. Browne, P. Roberts, R. Ruane, G. Tyler, L. Wopat, “Measurement of atmospheric wavefront distortion using scattered light from a laser guide star,” Nature (London) 353, 144–146 (1991); C. Primmerman, D. Murphy, D. Page, B. Zollars, H. Barclay, “Compensation of atmospheric optical distortion using a synthetic beacon,” Nature (London) 353, 141–143 (1991).
    [Crossref]
  4. C. D. Swift, J. W. Bergum, E. S. Bliss, F. A. House, M. A. Libkind, J. T. Salmon, C. L. Weinzapfel, “Zonal deformable mirror for laser wavefront control,” in Active and Adaptive Optical Components, M. A. Ealey, ed., Proc. Soc. Photo-Opt. Instrum. Eng.1543, 107–119 (1991).
    [Crossref]
  5. K. Avicola, J. M. Brase, J. R. Morris, H. D. Bissinger, J. M. Duff, H. W. Friedman, D. T. Gavel, C. E. Max, S. S. Olivier, R. W. Presta, D. A. Rapp, J. T. Salmon, K. E. Waltjen, “Sodium-layer laser-guide-star experimental results,” J. Opt. Soc. Am. A 11, 825–831 (1994).
    [Crossref]
  6. D. T. Gavel, J. R. Morris, R. G. Vernon, “Systematic design and analysis of laser-guide-star adaptive-optics systems for large telescopes,” J. Opt. Soc. Am. A 11, 914–924 (1994).
    [Crossref]
  7. J. R. Morris, “Efficient excitation of a mesospheric sodium laser guide star by intermediate-duration pulses,” J. Opt. Soc. Am. A 11, 832–845 (1994).
    [Crossref]
  8. S. S. Olivier, D. T. Gavel, “Tip–tilt compensation for astronomical imaging,” J. Opt. Soc. Am. A 11, 368–378 (1994).
    [Crossref]
  9. G. Megie, F. Bos, J. E. Blamont, M. L. Chanin, “Simultaneous nighttime lidar measurements of atmospheric sodium and potassium,” Planet. Space Sci. 26, 27–35 (1978).
    [Crossref]
  10. K. Avicola, J. T. Salmon, J. Brase, K. Waltjen, R. Presta, K. S. Balch, “High frame-rate, large field wavefront sensor,” in Proceedings of Laser Guide Star Adaptive Optics Workshop, R. Q. Fugate, ed. (U.S. Air Force Phillips Laboratory, Albuquerque, N.M., 1992), pp. 776–793.
  11. L. C. Bradley, “Pulse-train excitation of sodium for use as a synthetic beacon,” J. Opt. Soc. Am. B 9, 1931–1944 (1992).
    [Crossref]
  12. P. W. Milonni, L. E. Thode, “Theory of mesospheric sodium fluorescence excited by pulse trains,” Appl. Opt. 31, 785–800 (1992).
    [Crossref] [PubMed]
  13. B. M. Welsh, C. S. Gardner, “Nonlinear resonant absorption effects on the design of resonance fluorescence lidars and laser guide stars,” Appl. Opt. 28, 4141–4153 (1989); C. S. Gardner, D. G. Voelz, C. F. Sechrist, A. C. Segal, “Lidar studies of the nighttime sodium layer over Urbana, Illinois. 1. Seasonal and nocturnal variations,”J. Geophys. Res. 91, 13,659–13,673 (1986).
    [Crossref] [PubMed]
  14. M. Rushford, N. Thomas, R. Coombs, A. Gorski, R. Peterson, J. Toeppen, D. Porvitt, E. Dante, R. Susztar, J. Benterou, E. Ross, S. Abbitt, R. Sherwood, M. Gregonis, E. Diemer, P. Powers, R. Kane, Tri-Valley Stargazers, Livermore, Calif. 94551 (personal communication, 1992).
  15. N. Thomas, Lawrence Livermore National Laboratory, Livermore, Calif. 94550 (personal communication, 1992).
  16. C. B. Hogge, R. R. Butts, “Frequency spectra for the geometric representation of wavefront distortions due to atmospheric turbulence,”IEEE Trans. Antennas Propag. AP-24, 144–154 (1976).
    [Crossref]
  17. V. I. Tatarski, Wave Propagation in a Turbulent Medium (Dover, New York, 1961).
  18. G. A. Chanan, “Atmospheric seeing and its effect on the alignment of segmented and multiple mirror telescopes,” (W M. Keck Observatory, Kamuela, Hawaii, 1988).
  19. D. P. Greenwood, C. A. Primmerman, D. V. Murphy, “Measurements of atmospheric phase and tilt, and comparison with theory,” in Vol. 30 of Proceedings of European Southern Observatory Conference and Workshop on Very Large Telescopes and Their Instrumentation, M.-H. Ulrich, ed. (European Southern Observatory, Garching, Germany, 1988), pp. 675–682.
  20. D. S. Acton, R. J. Sharbough, J. R. Roehrig, D. Tiszauer, “Wave-front tilt power spectral density from the image motion of solar pores,” Appl. Opt. 31, 4280–4284 (1992).
    [Crossref] [PubMed]
  21. S. S. Olivier, C. E. Max, D. Gavel, J. Brase, “Tip–tilt compensation: resolution limits for ground based telescopes using laser guide star adaptive optics,” Astrophys. J. 407, 428–439 (1993).
    [Crossref]
  22. R. G. Vernon, D. Link, Science Applications International Corporation, Palm Beach Gardens, Fla. 33410 (personal communication, 1992).
  23. B. Ellerbroeck, “Adaptive optics performance predictions for astronomical applications under good seeing conditions,” in Proceedings of Laser Guide Star Adaptive Optics Workshop, R. Q. Fugate, ed. (U.S. Air Force Phillips Laboratory, Albuquerque, N.M., 1992), pp. 441–457.
  24. D. Fried, “Anisoplanatism in adaptive optics,”J. Opt. Soc. Am. 72, 52–61 (1982).
    [Crossref]
  25. R. Sasiela, “A unified approach to electromagnetic wave propagation in turbulence and the evaluation of multiparameter integrals,” (Lincoln Laboratory, Massachusetts Institute of Technology, Lexington, Mass., 1988).
  26. J. C. Twichell, B. E. Burke, R. K. Reich, W. H. McGonagle, C. M. Huang, M. E. Bautz, J. P. Dory, G. R. Reiker, R. W. Mountain, V. S. Dolat, “Advanced CCD imager technology for use from 1 to 10,000 Å,” Rev. Sci. Instrum. 61, 2744–2746 (1990).
    [Crossref]

1994 (5)

1993 (1)

S. S. Olivier, C. E. Max, D. Gavel, J. Brase, “Tip–tilt compensation: resolution limits for ground based telescopes using laser guide star adaptive optics,” Astrophys. J. 407, 428–439 (1993).
[Crossref]

1992 (3)

1991 (1)

R. Q. Fugate, D. Fried, G. Ameer, B. Boeke, S. Browne, P. Roberts, R. Ruane, G. Tyler, L. Wopat, “Measurement of atmospheric wavefront distortion using scattered light from a laser guide star,” Nature (London) 353, 144–146 (1991); C. Primmerman, D. Murphy, D. Page, B. Zollars, H. Barclay, “Compensation of atmospheric optical distortion using a synthetic beacon,” Nature (London) 353, 141–143 (1991).
[Crossref]

1990 (1)

J. C. Twichell, B. E. Burke, R. K. Reich, W. H. McGonagle, C. M. Huang, M. E. Bautz, J. P. Dory, G. R. Reiker, R. W. Mountain, V. S. Dolat, “Advanced CCD imager technology for use from 1 to 10,000 Å,” Rev. Sci. Instrum. 61, 2744–2746 (1990).
[Crossref]

1989 (1)

1985 (1)

R. Foy, A. Labeyrie, “Feasibility of adaptive optics telescope with laser probe,” Astron. Astrophys. 152, L29–L31 (1985); L. A. Thompson, C. S. Gardner, “Experiments on laser guide stars at Mauna Kea Observatory for adaptive imaging in astronomy,” Nature (London) 328, 229–231 (1987); R. A. Humphries, C. Primmerman, L. Bradley, J. Hermann, “Atmospheric turbulence measurements using a synthetic beacon in the mesospheric sodium layer,” Opt. Lett. 16, 1367–1369 (1991).
[Crossref]

1982 (1)

1978 (1)

G. Megie, F. Bos, J. E. Blamont, M. L. Chanin, “Simultaneous nighttime lidar measurements of atmospheric sodium and potassium,” Planet. Space Sci. 26, 27–35 (1978).
[Crossref]

1976 (1)

C. B. Hogge, R. R. Butts, “Frequency spectra for the geometric representation of wavefront distortions due to atmospheric turbulence,”IEEE Trans. Antennas Propag. AP-24, 144–154 (1976).
[Crossref]

Abbitt, S.

M. Rushford, N. Thomas, R. Coombs, A. Gorski, R. Peterson, J. Toeppen, D. Porvitt, E. Dante, R. Susztar, J. Benterou, E. Ross, S. Abbitt, R. Sherwood, M. Gregonis, E. Diemer, P. Powers, R. Kane, Tri-Valley Stargazers, Livermore, Calif. 94551 (personal communication, 1992).

Acton, D. S.

Ameer, G.

R. Q. Fugate, D. Fried, G. Ameer, B. Boeke, S. Browne, P. Roberts, R. Ruane, G. Tyler, L. Wopat, “Measurement of atmospheric wavefront distortion using scattered light from a laser guide star,” Nature (London) 353, 144–146 (1991); C. Primmerman, D. Murphy, D. Page, B. Zollars, H. Barclay, “Compensation of atmospheric optical distortion using a synthetic beacon,” Nature (London) 353, 141–143 (1991).
[Crossref]

Avicola, K.

K. Avicola, J. M. Brase, J. R. Morris, H. D. Bissinger, J. M. Duff, H. W. Friedman, D. T. Gavel, C. E. Max, S. S. Olivier, R. W. Presta, D. A. Rapp, J. T. Salmon, K. E. Waltjen, “Sodium-layer laser-guide-star experimental results,” J. Opt. Soc. Am. A 11, 825–831 (1994).
[Crossref]

K. Avicola, J. T. Salmon, J. Brase, K. Waltjen, R. Presta, K. S. Balch, “High frame-rate, large field wavefront sensor,” in Proceedings of Laser Guide Star Adaptive Optics Workshop, R. Q. Fugate, ed. (U.S. Air Force Phillips Laboratory, Albuquerque, N.M., 1992), pp. 776–793.

Balch, K. S.

K. Avicola, J. T. Salmon, J. Brase, K. Waltjen, R. Presta, K. S. Balch, “High frame-rate, large field wavefront sensor,” in Proceedings of Laser Guide Star Adaptive Optics Workshop, R. Q. Fugate, ed. (U.S. Air Force Phillips Laboratory, Albuquerque, N.M., 1992), pp. 776–793.

Bautz, M. E.

J. C. Twichell, B. E. Burke, R. K. Reich, W. H. McGonagle, C. M. Huang, M. E. Bautz, J. P. Dory, G. R. Reiker, R. W. Mountain, V. S. Dolat, “Advanced CCD imager technology for use from 1 to 10,000 Å,” Rev. Sci. Instrum. 61, 2744–2746 (1990).
[Crossref]

Benterou, J.

M. Rushford, N. Thomas, R. Coombs, A. Gorski, R. Peterson, J. Toeppen, D. Porvitt, E. Dante, R. Susztar, J. Benterou, E. Ross, S. Abbitt, R. Sherwood, M. Gregonis, E. Diemer, P. Powers, R. Kane, Tri-Valley Stargazers, Livermore, Calif. 94551 (personal communication, 1992).

Bergum, J. W.

C. D. Swift, J. W. Bergum, E. S. Bliss, F. A. House, M. A. Libkind, J. T. Salmon, C. L. Weinzapfel, “Zonal deformable mirror for laser wavefront control,” in Active and Adaptive Optical Components, M. A. Ealey, ed., Proc. Soc. Photo-Opt. Instrum. Eng.1543, 107–119 (1991).
[Crossref]

Bissinger, H. D.

Blamont, J. E.

G. Megie, F. Bos, J. E. Blamont, M. L. Chanin, “Simultaneous nighttime lidar measurements of atmospheric sodium and potassium,” Planet. Space Sci. 26, 27–35 (1978).
[Crossref]

Bliss, E. S.

C. D. Swift, J. W. Bergum, E. S. Bliss, F. A. House, M. A. Libkind, J. T. Salmon, C. L. Weinzapfel, “Zonal deformable mirror for laser wavefront control,” in Active and Adaptive Optical Components, M. A. Ealey, ed., Proc. Soc. Photo-Opt. Instrum. Eng.1543, 107–119 (1991).
[Crossref]

Boeke, B.

R. Q. Fugate, D. Fried, G. Ameer, B. Boeke, S. Browne, P. Roberts, R. Ruane, G. Tyler, L. Wopat, “Measurement of atmospheric wavefront distortion using scattered light from a laser guide star,” Nature (London) 353, 144–146 (1991); C. Primmerman, D. Murphy, D. Page, B. Zollars, H. Barclay, “Compensation of atmospheric optical distortion using a synthetic beacon,” Nature (London) 353, 141–143 (1991).
[Crossref]

Bos, F.

G. Megie, F. Bos, J. E. Blamont, M. L. Chanin, “Simultaneous nighttime lidar measurements of atmospheric sodium and potassium,” Planet. Space Sci. 26, 27–35 (1978).
[Crossref]

Bradley, L. C.

Brase, J.

S. S. Olivier, C. E. Max, D. Gavel, J. Brase, “Tip–tilt compensation: resolution limits for ground based telescopes using laser guide star adaptive optics,” Astrophys. J. 407, 428–439 (1993).
[Crossref]

K. Avicola, J. T. Salmon, J. Brase, K. Waltjen, R. Presta, K. S. Balch, “High frame-rate, large field wavefront sensor,” in Proceedings of Laser Guide Star Adaptive Optics Workshop, R. Q. Fugate, ed. (U.S. Air Force Phillips Laboratory, Albuquerque, N.M., 1992), pp. 776–793.

Brase, J. M.

Browne, S.

R. Q. Fugate, D. Fried, G. Ameer, B. Boeke, S. Browne, P. Roberts, R. Ruane, G. Tyler, L. Wopat, “Measurement of atmospheric wavefront distortion using scattered light from a laser guide star,” Nature (London) 353, 144–146 (1991); C. Primmerman, D. Murphy, D. Page, B. Zollars, H. Barclay, “Compensation of atmospheric optical distortion using a synthetic beacon,” Nature (London) 353, 141–143 (1991).
[Crossref]

Burke, B. E.

J. C. Twichell, B. E. Burke, R. K. Reich, W. H. McGonagle, C. M. Huang, M. E. Bautz, J. P. Dory, G. R. Reiker, R. W. Mountain, V. S. Dolat, “Advanced CCD imager technology for use from 1 to 10,000 Å,” Rev. Sci. Instrum. 61, 2744–2746 (1990).
[Crossref]

Butts, R. R.

C. B. Hogge, R. R. Butts, “Frequency spectra for the geometric representation of wavefront distortions due to atmospheric turbulence,”IEEE Trans. Antennas Propag. AP-24, 144–154 (1976).
[Crossref]

Chanan, G. A.

G. A. Chanan, “Atmospheric seeing and its effect on the alignment of segmented and multiple mirror telescopes,” (W M. Keck Observatory, Kamuela, Hawaii, 1988).

Chanin, M. L.

G. Megie, F. Bos, J. E. Blamont, M. L. Chanin, “Simultaneous nighttime lidar measurements of atmospheric sodium and potassium,” Planet. Space Sci. 26, 27–35 (1978).
[Crossref]

Coombs, R.

M. Rushford, N. Thomas, R. Coombs, A. Gorski, R. Peterson, J. Toeppen, D. Porvitt, E. Dante, R. Susztar, J. Benterou, E. Ross, S. Abbitt, R. Sherwood, M. Gregonis, E. Diemer, P. Powers, R. Kane, Tri-Valley Stargazers, Livermore, Calif. 94551 (personal communication, 1992).

Dante, E.

M. Rushford, N. Thomas, R. Coombs, A. Gorski, R. Peterson, J. Toeppen, D. Porvitt, E. Dante, R. Susztar, J. Benterou, E. Ross, S. Abbitt, R. Sherwood, M. Gregonis, E. Diemer, P. Powers, R. Kane, Tri-Valley Stargazers, Livermore, Calif. 94551 (personal communication, 1992).

Diemer, E.

M. Rushford, N. Thomas, R. Coombs, A. Gorski, R. Peterson, J. Toeppen, D. Porvitt, E. Dante, R. Susztar, J. Benterou, E. Ross, S. Abbitt, R. Sherwood, M. Gregonis, E. Diemer, P. Powers, R. Kane, Tri-Valley Stargazers, Livermore, Calif. 94551 (personal communication, 1992).

Dolat, V. S.

J. C. Twichell, B. E. Burke, R. K. Reich, W. H. McGonagle, C. M. Huang, M. E. Bautz, J. P. Dory, G. R. Reiker, R. W. Mountain, V. S. Dolat, “Advanced CCD imager technology for use from 1 to 10,000 Å,” Rev. Sci. Instrum. 61, 2744–2746 (1990).
[Crossref]

Dory, J. P.

J. C. Twichell, B. E. Burke, R. K. Reich, W. H. McGonagle, C. M. Huang, M. E. Bautz, J. P. Dory, G. R. Reiker, R. W. Mountain, V. S. Dolat, “Advanced CCD imager technology for use from 1 to 10,000 Å,” Rev. Sci. Instrum. 61, 2744–2746 (1990).
[Crossref]

Duff, J. M.

Dyson, F.

Ellerbroeck, B.

B. Ellerbroeck, “Adaptive optics performance predictions for astronomical applications under good seeing conditions,” in Proceedings of Laser Guide Star Adaptive Optics Workshop, R. Q. Fugate, ed. (U.S. Air Force Phillips Laboratory, Albuquerque, N.M., 1992), pp. 441–457.

Foy, R.

R. Foy, A. Labeyrie, “Feasibility of adaptive optics telescope with laser probe,” Astron. Astrophys. 152, L29–L31 (1985); L. A. Thompson, C. S. Gardner, “Experiments on laser guide stars at Mauna Kea Observatory for adaptive imaging in astronomy,” Nature (London) 328, 229–231 (1987); R. A. Humphries, C. Primmerman, L. Bradley, J. Hermann, “Atmospheric turbulence measurements using a synthetic beacon in the mesospheric sodium layer,” Opt. Lett. 16, 1367–1369 (1991).
[Crossref]

Fried, D.

R. Q. Fugate, D. Fried, G. Ameer, B. Boeke, S. Browne, P. Roberts, R. Ruane, G. Tyler, L. Wopat, “Measurement of atmospheric wavefront distortion using scattered light from a laser guide star,” Nature (London) 353, 144–146 (1991); C. Primmerman, D. Murphy, D. Page, B. Zollars, H. Barclay, “Compensation of atmospheric optical distortion using a synthetic beacon,” Nature (London) 353, 141–143 (1991).
[Crossref]

D. Fried, “Anisoplanatism in adaptive optics,”J. Opt. Soc. Am. 72, 52–61 (1982).
[Crossref]

Friedman, H. W.

Fugate, R. Q.

R. Q. Fugate, D. Fried, G. Ameer, B. Boeke, S. Browne, P. Roberts, R. Ruane, G. Tyler, L. Wopat, “Measurement of atmospheric wavefront distortion using scattered light from a laser guide star,” Nature (London) 353, 144–146 (1991); C. Primmerman, D. Murphy, D. Page, B. Zollars, H. Barclay, “Compensation of atmospheric optical distortion using a synthetic beacon,” Nature (London) 353, 141–143 (1991).
[Crossref]

Gardner, C. S.

Gavel, D.

S. S. Olivier, C. E. Max, D. Gavel, J. Brase, “Tip–tilt compensation: resolution limits for ground based telescopes using laser guide star adaptive optics,” Astrophys. J. 407, 428–439 (1993).
[Crossref]

Gavel, D. T.

Gorski, A.

M. Rushford, N. Thomas, R. Coombs, A. Gorski, R. Peterson, J. Toeppen, D. Porvitt, E. Dante, R. Susztar, J. Benterou, E. Ross, S. Abbitt, R. Sherwood, M. Gregonis, E. Diemer, P. Powers, R. Kane, Tri-Valley Stargazers, Livermore, Calif. 94551 (personal communication, 1992).

Greenwood, D. P.

D. P. Greenwood, C. A. Primmerman, D. V. Murphy, “Measurements of atmospheric phase and tilt, and comparison with theory,” in Vol. 30 of Proceedings of European Southern Observatory Conference and Workshop on Very Large Telescopes and Their Instrumentation, M.-H. Ulrich, ed. (European Southern Observatory, Garching, Germany, 1988), pp. 675–682.

Gregonis, M.

M. Rushford, N. Thomas, R. Coombs, A. Gorski, R. Peterson, J. Toeppen, D. Porvitt, E. Dante, R. Susztar, J. Benterou, E. Ross, S. Abbitt, R. Sherwood, M. Gregonis, E. Diemer, P. Powers, R. Kane, Tri-Valley Stargazers, Livermore, Calif. 94551 (personal communication, 1992).

Happer, W.

Hogge, C. B.

C. B. Hogge, R. R. Butts, “Frequency spectra for the geometric representation of wavefront distortions due to atmospheric turbulence,”IEEE Trans. Antennas Propag. AP-24, 144–154 (1976).
[Crossref]

House, F. A.

C. D. Swift, J. W. Bergum, E. S. Bliss, F. A. House, M. A. Libkind, J. T. Salmon, C. L. Weinzapfel, “Zonal deformable mirror for laser wavefront control,” in Active and Adaptive Optical Components, M. A. Ealey, ed., Proc. Soc. Photo-Opt. Instrum. Eng.1543, 107–119 (1991).
[Crossref]

Huang, C. M.

J. C. Twichell, B. E. Burke, R. K. Reich, W. H. McGonagle, C. M. Huang, M. E. Bautz, J. P. Dory, G. R. Reiker, R. W. Mountain, V. S. Dolat, “Advanced CCD imager technology for use from 1 to 10,000 Å,” Rev. Sci. Instrum. 61, 2744–2746 (1990).
[Crossref]

Kane, R.

M. Rushford, N. Thomas, R. Coombs, A. Gorski, R. Peterson, J. Toeppen, D. Porvitt, E. Dante, R. Susztar, J. Benterou, E. Ross, S. Abbitt, R. Sherwood, M. Gregonis, E. Diemer, P. Powers, R. Kane, Tri-Valley Stargazers, Livermore, Calif. 94551 (personal communication, 1992).

Labeyrie, A.

R. Foy, A. Labeyrie, “Feasibility of adaptive optics telescope with laser probe,” Astron. Astrophys. 152, L29–L31 (1985); L. A. Thompson, C. S. Gardner, “Experiments on laser guide stars at Mauna Kea Observatory for adaptive imaging in astronomy,” Nature (London) 328, 229–231 (1987); R. A. Humphries, C. Primmerman, L. Bradley, J. Hermann, “Atmospheric turbulence measurements using a synthetic beacon in the mesospheric sodium layer,” Opt. Lett. 16, 1367–1369 (1991).
[Crossref]

Libkind, M. A.

C. D. Swift, J. W. Bergum, E. S. Bliss, F. A. House, M. A. Libkind, J. T. Salmon, C. L. Weinzapfel, “Zonal deformable mirror for laser wavefront control,” in Active and Adaptive Optical Components, M. A. Ealey, ed., Proc. Soc. Photo-Opt. Instrum. Eng.1543, 107–119 (1991).
[Crossref]

Link, D.

R. G. Vernon, D. Link, Science Applications International Corporation, Palm Beach Gardens, Fla. 33410 (personal communication, 1992).

MacDonald, G.

Max, C.

Max, C. E.

K. Avicola, J. M. Brase, J. R. Morris, H. D. Bissinger, J. M. Duff, H. W. Friedman, D. T. Gavel, C. E. Max, S. S. Olivier, R. W. Presta, D. A. Rapp, J. T. Salmon, K. E. Waltjen, “Sodium-layer laser-guide-star experimental results,” J. Opt. Soc. Am. A 11, 825–831 (1994).
[Crossref]

S. S. Olivier, C. E. Max, D. Gavel, J. Brase, “Tip–tilt compensation: resolution limits for ground based telescopes using laser guide star adaptive optics,” Astrophys. J. 407, 428–439 (1993).
[Crossref]

McGonagle, W. H.

J. C. Twichell, B. E. Burke, R. K. Reich, W. H. McGonagle, C. M. Huang, M. E. Bautz, J. P. Dory, G. R. Reiker, R. W. Mountain, V. S. Dolat, “Advanced CCD imager technology for use from 1 to 10,000 Å,” Rev. Sci. Instrum. 61, 2744–2746 (1990).
[Crossref]

Megie, G.

G. Megie, F. Bos, J. E. Blamont, M. L. Chanin, “Simultaneous nighttime lidar measurements of atmospheric sodium and potassium,” Planet. Space Sci. 26, 27–35 (1978).
[Crossref]

Milonni, P. W.

Morris, J. R.

Mountain, R. W.

J. C. Twichell, B. E. Burke, R. K. Reich, W. H. McGonagle, C. M. Huang, M. E. Bautz, J. P. Dory, G. R. Reiker, R. W. Mountain, V. S. Dolat, “Advanced CCD imager technology for use from 1 to 10,000 Å,” Rev. Sci. Instrum. 61, 2744–2746 (1990).
[Crossref]

Murphy, D. V.

D. P. Greenwood, C. A. Primmerman, D. V. Murphy, “Measurements of atmospheric phase and tilt, and comparison with theory,” in Vol. 30 of Proceedings of European Southern Observatory Conference and Workshop on Very Large Telescopes and Their Instrumentation, M.-H. Ulrich, ed. (European Southern Observatory, Garching, Germany, 1988), pp. 675–682.

Olivier, S. S.

Peterson, R.

M. Rushford, N. Thomas, R. Coombs, A. Gorski, R. Peterson, J. Toeppen, D. Porvitt, E. Dante, R. Susztar, J. Benterou, E. Ross, S. Abbitt, R. Sherwood, M. Gregonis, E. Diemer, P. Powers, R. Kane, Tri-Valley Stargazers, Livermore, Calif. 94551 (personal communication, 1992).

Porvitt, D.

M. Rushford, N. Thomas, R. Coombs, A. Gorski, R. Peterson, J. Toeppen, D. Porvitt, E. Dante, R. Susztar, J. Benterou, E. Ross, S. Abbitt, R. Sherwood, M. Gregonis, E. Diemer, P. Powers, R. Kane, Tri-Valley Stargazers, Livermore, Calif. 94551 (personal communication, 1992).

Powers, P.

M. Rushford, N. Thomas, R. Coombs, A. Gorski, R. Peterson, J. Toeppen, D. Porvitt, E. Dante, R. Susztar, J. Benterou, E. Ross, S. Abbitt, R. Sherwood, M. Gregonis, E. Diemer, P. Powers, R. Kane, Tri-Valley Stargazers, Livermore, Calif. 94551 (personal communication, 1992).

Presta, R.

K. Avicola, J. T. Salmon, J. Brase, K. Waltjen, R. Presta, K. S. Balch, “High frame-rate, large field wavefront sensor,” in Proceedings of Laser Guide Star Adaptive Optics Workshop, R. Q. Fugate, ed. (U.S. Air Force Phillips Laboratory, Albuquerque, N.M., 1992), pp. 776–793.

Presta, R. W.

Primmerman, C. A.

D. P. Greenwood, C. A. Primmerman, D. V. Murphy, “Measurements of atmospheric phase and tilt, and comparison with theory,” in Vol. 30 of Proceedings of European Southern Observatory Conference and Workshop on Very Large Telescopes and Their Instrumentation, M.-H. Ulrich, ed. (European Southern Observatory, Garching, Germany, 1988), pp. 675–682.

Rapp, D. A.

Reich, R. K.

J. C. Twichell, B. E. Burke, R. K. Reich, W. H. McGonagle, C. M. Huang, M. E. Bautz, J. P. Dory, G. R. Reiker, R. W. Mountain, V. S. Dolat, “Advanced CCD imager technology for use from 1 to 10,000 Å,” Rev. Sci. Instrum. 61, 2744–2746 (1990).
[Crossref]

Reiker, G. R.

J. C. Twichell, B. E. Burke, R. K. Reich, W. H. McGonagle, C. M. Huang, M. E. Bautz, J. P. Dory, G. R. Reiker, R. W. Mountain, V. S. Dolat, “Advanced CCD imager technology for use from 1 to 10,000 Å,” Rev. Sci. Instrum. 61, 2744–2746 (1990).
[Crossref]

Roberts, P.

R. Q. Fugate, D. Fried, G. Ameer, B. Boeke, S. Browne, P. Roberts, R. Ruane, G. Tyler, L. Wopat, “Measurement of atmospheric wavefront distortion using scattered light from a laser guide star,” Nature (London) 353, 144–146 (1991); C. Primmerman, D. Murphy, D. Page, B. Zollars, H. Barclay, “Compensation of atmospheric optical distortion using a synthetic beacon,” Nature (London) 353, 141–143 (1991).
[Crossref]

Roehrig, J. R.

Ross, E.

M. Rushford, N. Thomas, R. Coombs, A. Gorski, R. Peterson, J. Toeppen, D. Porvitt, E. Dante, R. Susztar, J. Benterou, E. Ross, S. Abbitt, R. Sherwood, M. Gregonis, E. Diemer, P. Powers, R. Kane, Tri-Valley Stargazers, Livermore, Calif. 94551 (personal communication, 1992).

Ruane, R.

R. Q. Fugate, D. Fried, G. Ameer, B. Boeke, S. Browne, P. Roberts, R. Ruane, G. Tyler, L. Wopat, “Measurement of atmospheric wavefront distortion using scattered light from a laser guide star,” Nature (London) 353, 144–146 (1991); C. Primmerman, D. Murphy, D. Page, B. Zollars, H. Barclay, “Compensation of atmospheric optical distortion using a synthetic beacon,” Nature (London) 353, 141–143 (1991).
[Crossref]

Rushford, M.

M. Rushford, N. Thomas, R. Coombs, A. Gorski, R. Peterson, J. Toeppen, D. Porvitt, E. Dante, R. Susztar, J. Benterou, E. Ross, S. Abbitt, R. Sherwood, M. Gregonis, E. Diemer, P. Powers, R. Kane, Tri-Valley Stargazers, Livermore, Calif. 94551 (personal communication, 1992).

Salmon, J. T.

K. Avicola, J. M. Brase, J. R. Morris, H. D. Bissinger, J. M. Duff, H. W. Friedman, D. T. Gavel, C. E. Max, S. S. Olivier, R. W. Presta, D. A. Rapp, J. T. Salmon, K. E. Waltjen, “Sodium-layer laser-guide-star experimental results,” J. Opt. Soc. Am. A 11, 825–831 (1994).
[Crossref]

K. Avicola, J. T. Salmon, J. Brase, K. Waltjen, R. Presta, K. S. Balch, “High frame-rate, large field wavefront sensor,” in Proceedings of Laser Guide Star Adaptive Optics Workshop, R. Q. Fugate, ed. (U.S. Air Force Phillips Laboratory, Albuquerque, N.M., 1992), pp. 776–793.

C. D. Swift, J. W. Bergum, E. S. Bliss, F. A. House, M. A. Libkind, J. T. Salmon, C. L. Weinzapfel, “Zonal deformable mirror for laser wavefront control,” in Active and Adaptive Optical Components, M. A. Ealey, ed., Proc. Soc. Photo-Opt. Instrum. Eng.1543, 107–119 (1991).
[Crossref]

Sasiela, R.

R. Sasiela, “A unified approach to electromagnetic wave propagation in turbulence and the evaluation of multiparameter integrals,” (Lincoln Laboratory, Massachusetts Institute of Technology, Lexington, Mass., 1988).

Sharbough, R. J.

Sherwood, R.

M. Rushford, N. Thomas, R. Coombs, A. Gorski, R. Peterson, J. Toeppen, D. Porvitt, E. Dante, R. Susztar, J. Benterou, E. Ross, S. Abbitt, R. Sherwood, M. Gregonis, E. Diemer, P. Powers, R. Kane, Tri-Valley Stargazers, Livermore, Calif. 94551 (personal communication, 1992).

Susztar, R.

M. Rushford, N. Thomas, R. Coombs, A. Gorski, R. Peterson, J. Toeppen, D. Porvitt, E. Dante, R. Susztar, J. Benterou, E. Ross, S. Abbitt, R. Sherwood, M. Gregonis, E. Diemer, P. Powers, R. Kane, Tri-Valley Stargazers, Livermore, Calif. 94551 (personal communication, 1992).

Swift, C. D.

C. D. Swift, J. W. Bergum, E. S. Bliss, F. A. House, M. A. Libkind, J. T. Salmon, C. L. Weinzapfel, “Zonal deformable mirror for laser wavefront control,” in Active and Adaptive Optical Components, M. A. Ealey, ed., Proc. Soc. Photo-Opt. Instrum. Eng.1543, 107–119 (1991).
[Crossref]

Tatarski, V. I.

V. I. Tatarski, Wave Propagation in a Turbulent Medium (Dover, New York, 1961).

Thode, L. E.

Thomas, N.

N. Thomas, Lawrence Livermore National Laboratory, Livermore, Calif. 94550 (personal communication, 1992).

M. Rushford, N. Thomas, R. Coombs, A. Gorski, R. Peterson, J. Toeppen, D. Porvitt, E. Dante, R. Susztar, J. Benterou, E. Ross, S. Abbitt, R. Sherwood, M. Gregonis, E. Diemer, P. Powers, R. Kane, Tri-Valley Stargazers, Livermore, Calif. 94551 (personal communication, 1992).

Tiszauer, D.

Toeppen, J.

M. Rushford, N. Thomas, R. Coombs, A. Gorski, R. Peterson, J. Toeppen, D. Porvitt, E. Dante, R. Susztar, J. Benterou, E. Ross, S. Abbitt, R. Sherwood, M. Gregonis, E. Diemer, P. Powers, R. Kane, Tri-Valley Stargazers, Livermore, Calif. 94551 (personal communication, 1992).

Twichell, J. C.

J. C. Twichell, B. E. Burke, R. K. Reich, W. H. McGonagle, C. M. Huang, M. E. Bautz, J. P. Dory, G. R. Reiker, R. W. Mountain, V. S. Dolat, “Advanced CCD imager technology for use from 1 to 10,000 Å,” Rev. Sci. Instrum. 61, 2744–2746 (1990).
[Crossref]

Tyler, G.

R. Q. Fugate, D. Fried, G. Ameer, B. Boeke, S. Browne, P. Roberts, R. Ruane, G. Tyler, L. Wopat, “Measurement of atmospheric wavefront distortion using scattered light from a laser guide star,” Nature (London) 353, 144–146 (1991); C. Primmerman, D. Murphy, D. Page, B. Zollars, H. Barclay, “Compensation of atmospheric optical distortion using a synthetic beacon,” Nature (London) 353, 141–143 (1991).
[Crossref]

Vernon, R. G.

D. T. Gavel, J. R. Morris, R. G. Vernon, “Systematic design and analysis of laser-guide-star adaptive-optics systems for large telescopes,” J. Opt. Soc. Am. A 11, 914–924 (1994).
[Crossref]

R. G. Vernon, D. Link, Science Applications International Corporation, Palm Beach Gardens, Fla. 33410 (personal communication, 1992).

Waltjen, K.

K. Avicola, J. T. Salmon, J. Brase, K. Waltjen, R. Presta, K. S. Balch, “High frame-rate, large field wavefront sensor,” in Proceedings of Laser Guide Star Adaptive Optics Workshop, R. Q. Fugate, ed. (U.S. Air Force Phillips Laboratory, Albuquerque, N.M., 1992), pp. 776–793.

Waltjen, K. E.

Weinzapfel, C. L.

C. D. Swift, J. W. Bergum, E. S. Bliss, F. A. House, M. A. Libkind, J. T. Salmon, C. L. Weinzapfel, “Zonal deformable mirror for laser wavefront control,” in Active and Adaptive Optical Components, M. A. Ealey, ed., Proc. Soc. Photo-Opt. Instrum. Eng.1543, 107–119 (1991).
[Crossref]

Welsh, B. M.

Wopat, L.

R. Q. Fugate, D. Fried, G. Ameer, B. Boeke, S. Browne, P. Roberts, R. Ruane, G. Tyler, L. Wopat, “Measurement of atmospheric wavefront distortion using scattered light from a laser guide star,” Nature (London) 353, 144–146 (1991); C. Primmerman, D. Murphy, D. Page, B. Zollars, H. Barclay, “Compensation of atmospheric optical distortion using a synthetic beacon,” Nature (London) 353, 141–143 (1991).
[Crossref]

Appl. Opt. (3)

Astron. Astrophys. (1)

R. Foy, A. Labeyrie, “Feasibility of adaptive optics telescope with laser probe,” Astron. Astrophys. 152, L29–L31 (1985); L. A. Thompson, C. S. Gardner, “Experiments on laser guide stars at Mauna Kea Observatory for adaptive imaging in astronomy,” Nature (London) 328, 229–231 (1987); R. A. Humphries, C. Primmerman, L. Bradley, J. Hermann, “Atmospheric turbulence measurements using a synthetic beacon in the mesospheric sodium layer,” Opt. Lett. 16, 1367–1369 (1991).
[Crossref]

Astrophys. J. (1)

S. S. Olivier, C. E. Max, D. Gavel, J. Brase, “Tip–tilt compensation: resolution limits for ground based telescopes using laser guide star adaptive optics,” Astrophys. J. 407, 428–439 (1993).
[Crossref]

IEEE Trans. Antennas Propag. (1)

C. B. Hogge, R. R. Butts, “Frequency spectra for the geometric representation of wavefront distortions due to atmospheric turbulence,”IEEE Trans. Antennas Propag. AP-24, 144–154 (1976).
[Crossref]

J. Opt. Soc. Am. (1)

J. Opt. Soc. Am. A (5)

J. Opt. Soc. Am. B (1)

Nature (London) (1)

R. Q. Fugate, D. Fried, G. Ameer, B. Boeke, S. Browne, P. Roberts, R. Ruane, G. Tyler, L. Wopat, “Measurement of atmospheric wavefront distortion using scattered light from a laser guide star,” Nature (London) 353, 144–146 (1991); C. Primmerman, D. Murphy, D. Page, B. Zollars, H. Barclay, “Compensation of atmospheric optical distortion using a synthetic beacon,” Nature (London) 353, 141–143 (1991).
[Crossref]

Planet. Space Sci. (1)

G. Megie, F. Bos, J. E. Blamont, M. L. Chanin, “Simultaneous nighttime lidar measurements of atmospheric sodium and potassium,” Planet. Space Sci. 26, 27–35 (1978).
[Crossref]

Rev. Sci. Instrum. (1)

J. C. Twichell, B. E. Burke, R. K. Reich, W. H. McGonagle, C. M. Huang, M. E. Bautz, J. P. Dory, G. R. Reiker, R. W. Mountain, V. S. Dolat, “Advanced CCD imager technology for use from 1 to 10,000 Å,” Rev. Sci. Instrum. 61, 2744–2746 (1990).
[Crossref]

Other (10)

R. Sasiela, “A unified approach to electromagnetic wave propagation in turbulence and the evaluation of multiparameter integrals,” (Lincoln Laboratory, Massachusetts Institute of Technology, Lexington, Mass., 1988).

R. G. Vernon, D. Link, Science Applications International Corporation, Palm Beach Gardens, Fla. 33410 (personal communication, 1992).

B. Ellerbroeck, “Adaptive optics performance predictions for astronomical applications under good seeing conditions,” in Proceedings of Laser Guide Star Adaptive Optics Workshop, R. Q. Fugate, ed. (U.S. Air Force Phillips Laboratory, Albuquerque, N.M., 1992), pp. 441–457.

K. Avicola, J. T. Salmon, J. Brase, K. Waltjen, R. Presta, K. S. Balch, “High frame-rate, large field wavefront sensor,” in Proceedings of Laser Guide Star Adaptive Optics Workshop, R. Q. Fugate, ed. (U.S. Air Force Phillips Laboratory, Albuquerque, N.M., 1992), pp. 776–793.

C. D. Swift, J. W. Bergum, E. S. Bliss, F. A. House, M. A. Libkind, J. T. Salmon, C. L. Weinzapfel, “Zonal deformable mirror for laser wavefront control,” in Active and Adaptive Optical Components, M. A. Ealey, ed., Proc. Soc. Photo-Opt. Instrum. Eng.1543, 107–119 (1991).
[Crossref]

V. I. Tatarski, Wave Propagation in a Turbulent Medium (Dover, New York, 1961).

G. A. Chanan, “Atmospheric seeing and its effect on the alignment of segmented and multiple mirror telescopes,” (W M. Keck Observatory, Kamuela, Hawaii, 1988).

D. P. Greenwood, C. A. Primmerman, D. V. Murphy, “Measurements of atmospheric phase and tilt, and comparison with theory,” in Vol. 30 of Proceedings of European Southern Observatory Conference and Workshop on Very Large Telescopes and Their Instrumentation, M.-H. Ulrich, ed. (European Southern Observatory, Garching, Germany, 1988), pp. 675–682.

M. Rushford, N. Thomas, R. Coombs, A. Gorski, R. Peterson, J. Toeppen, D. Porvitt, E. Dante, R. Susztar, J. Benterou, E. Ross, S. Abbitt, R. Sherwood, M. Gregonis, E. Diemer, P. Powers, R. Kane, Tri-Valley Stargazers, Livermore, Calif. 94551 (personal communication, 1992).

N. Thomas, Lawrence Livermore National Laboratory, Livermore, Calif. 94550 (personal communication, 1992).

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Figures (23)

Fig. 1
Fig. 1

Schematic illustration of the laser-beam-director configuration for achieving spatial separation of the sodium-layer guide star at a 95-km altitude from the Rayleigh-scattered light at lower altitudes.

Fig. 2
Fig. 2

Conceptual design of the LLNL AVLIS laser system. Twelve chains of CVL’s are used to pump three chains of dye lasers. For the sodium-guide-star application only one chain of dye lasers is used; this is tuned to 589 nm. The CVL chains, each of which operates at a pulse-repetition rate of 4.3 kHz, are time multiplexed in the dye laser to produce the overall 26-kHz system repetition rate.

Fig. 3
Fig. 3

Photograph of one amplifier unit of the LLNL CVL system used in this experiment. This laser amplifier routinely achieves 300 W of average power with a wall-plug efficiency of 1%. A chain consisting of three of these amplifiers and an oscillator typically delivers an average power of 750 W and is stable for more than 1000 h.

Fig. 4
Fig. 4

LLNL CVL system output: laser power versus time. This system consists of 12 chains of CVL’s that have been in operation on a round-the-clock basis for several years.

Fig. 5
Fig. 5

AVLIS dye-laser system characteristics: laser power versus time. For the experiment described in this paper, the dye chain was tuned to the sodium wavelength of 589 nm and produced ~1400 W of average power at the output of the last dye amplifier. Approximately 1100 W of power was available for projection into the atmosphere.

Fig. 6
Fig. 6

Long-term frequency stability of the AVLIS dye lasers. The control system routinely locks the dye laser to within ±1 × 10−7 of the atomic-resonance frequency for days at a time.

Fig. 7
Fig. 7

Typical wave-front flatness of the AVLIS high-power dye-laser chain. The beam quality corresponds to a peak-to-peak distortion of 0.16λ or an rms distortion of 0.03λ, which has a Strehl ratio ≥0.90.

Fig. 8
Fig. 8

Pulse-stretcher topology. This concept provides for a factor-of-16 stretch in the laser pulse length, employing four White cells with delays of 1, 2, 4, and 8 times the initial pulse duration. An attenuation of the final pulse of only 11% is predicted for AVLIS mirrors, which have a demonstrated reflectivity of 0.998.

Fig. 9
Fig. 9

First laboratory results from the pulse stretcher at low laser power (1 W). As each delay cell is unblocked, more pulses appear in the output, with each pulse having a lower peak power. With four White cells the pulse train consists of 16 pulses and has a total duration of 960 ns.

Fig. 10
Fig. 10

Visualization of data from a CCD image of the Rayleigh-scattered light (right) and the sodium laser guide star (toward the center of the frame) at the LLNL site, for an average laser power of 32 W The exposure time was 12 s on the quarter-meter telescope with the Photometrics camera. The FWHM of the sodium-guide-star image was ~5 arcsec, and the seeing was 3.3 arcsec.

Fig. 11
Fig. 11

Photon flux observed at the aperture of the half-meter telescope as a function of laser power. The data points are derived from photometric experiments. The solid curve is an atomic-physics model calculation with the 24-level Bloch-equation model that is described in Ref. 7.

Fig. 12
Fig. 12

Predicted sodium-guide-star apparent magnitude, from a calculation with the 24-level Bloch-equation model given in Ref. 7. The lower curve is for a stretched laser pulse (stretch factor equal to 16), and the upper curve is for our present unstretched laser pulse. The prediction of the upper curve that the guide star should be fifth magnitude at laser powers of ~1 kW is consistent with the reports of nearby visual observers and amateur astronomers.

Fig. 13
Fig. 13

Power spectrum of wave-front tilts obtained from (a) a laser guide star and (b) a natural star under the same conditions as in Plates 4 and 5. The data for the laser-guide-star tilt spectrum are limited to frequencies that are lower than those of the natural star, since the integration time for the laser guide star was 5 rather than 1 ms. Both power spectra show the characteristic ω−2/3 frequency scaling that is predicted for Kolmogorov turbulence at low frequencies, as indicated by the gray line and by the gray line in the left-hand side of (b). The shaded line in the right-hand side of (b) corresponds to a ν−8/3 frequency scaling. At frequencies higher than ~100 Hz the natural-star tilt spectrum begins to flatten, corresponding to the onset of a noise floor.

Fig. 14
Fig. 14

Superposition of tilt power spectra from the laser guide star (gray curve) and the natural star (black curve). The data are as in Fig. 13. The laser-guide-star data extend only to 60 Hz because of the slower sampling frequency. The slightly higher tilt-spectrum amplitudes for the laser-guide-star data between 20 and 60 Hz suggest that the noise floor for the laser-guide-star power spectrum is higher than that for the natural star.

Fig. 15
Fig. 15

Predicted Strehl ratio versus laser power for the half-meter telescope and an observing wavelength of 0.8 μm at LLNL. Subaperture spacing is assumed to be 10 cm, and the wave-front-sensor parameters are taken to be those of our Kodak intensified-CCD camera, which has high gain but a low quantum efficiency (5%). For the unstretched laser pulse (lower curve), we used the sodium-guide-star return flux from our experimental data; at each power level the wave-front-sensor sample rate was optimized for maximum Strehl ratio. For the case in which the laser pulse length has been stretched by a factor of 16 (upper curve), the guide-star return was that predicted by our atomic-physics model,7 and the wave-front sample rate was 220 Hz. In both cases the sample rate fs was assumed to be ten times the closed-loop bandwidth fc.

Fig. 16
Fig. 16

Predicted Strehl ratio versus observing wavelength for the half-meter telescope at LLNL, with natural guide stars as a wave-front reference. The wave-front-sensor parameters are assumed to be those of our Kodak intensified-CCD camera (5% quantum efficiency), sensing at a center wavelength of 0.55 pm with a 100 nm FWHM filter. The subaperture size is assumed to be 10 cm for both the deformable mirror and the wave-front sensor. The stellar magnitudes m and the closed-cycle bandwidths fc that were used for these calculations were (m = 1, fc = 72 Hz), (m = 3, fc = 72 Hz), (m = 4, fc = 72 Hz), (m = 5, fc = 36 Hz). In each case the sampling frequency fs was ten times fc.

Fig. 17
Fig. 17

Predicted Strehl ratio versus observing wavelength for the same conditions as in Fig. 16 but with a high-quantum-efficiency low-noise CCD camera as a wave-front sensor (80% quantum efficiency, 10 electrons of read noise). The wave-front sensor’s center wavelength was 0.55 pm with a 100-nm FWHM filter. The stellar magnitudes m and the closed-cycle bandwidths fc that were used for these calculations were (m = 3, fc = 72 Hz), (m = 5, fc = 72 Hz), (m = 7, fc = 42 Hz), (m = 9, fc = 11 Hz).

Plate 1
Plate 1

LLNL laser-guide-star site at night, showing the vertical beam-director pipe (center), the half-meter telescope (right), and the quarter-meter telescope (lower black telescope between the beam pipe and the half-meter telescope). In this somewhat overexposed image the control room appears to be red because of the red lighting that was used to facilitate dark adaptation. The tent that shelters the telescopes and the control room is seen folded back at the rear of the beam pipe.

Plate 2
Plate 2

Photograph of a portion of the AVLIS dye-laser system. This system, which was used for the experiments that are described in the present paper, uses conventional optics to transport the green CVL-pump light to the dye lasers. A fiber-optic delivery system has recently been developed that simplifies this beam transport. The fiber-optic delivery system would be quite useful, on a smaller, fieldable beacon-laser system for astronomy applications, to simplify alignment and to permit the CVL-pump laser system to be located a considerable distance away so as to avoid perturbations that are due to waste heat.

Plate 3
Plate 3

Image of the sodium guide star, located 4.4 km from the LLNL site, that was obtained by A. Gorski of the Tri-Valley Stargazers Club with an 8-in. (20.3-cm) Schmidt camera on August 26, 1992. The image was photographed on Kodak Ektachrome 400 film and was taken in a 4-min exposure. The spatial extent of the guide star corresponds to the published thickness of the sodium layer, ~10 km.

Plate 4
Plate 4

Pattern of Hartmann spots on the wave-front sensor, from a sodium-layer laser guide star with laser power of 875 W. (a) A single frame with 5-ms exposure time (taken from a series with a frame rate of 125 Hz). (b) The average of 100 frames.

Plate 5
Plate 5

Pattern of Hartmann spots on the wave-front sensor, from the natural star Capella of apparent visual magnitude 0.1, recorded with a 40-nm filter centered at 500 nm. (a) A single frame with 1-ms exposure time (recorded from a series with a frame rate of 1000 Hz). (b) The average of 100 frames.

Plate 6
Plate 6

Sequences of three consecutive reconstructed wave fronts from a natural star (top row) and a laser guide star (bottom row). For both the natural- and the laser-star sequences, the wave-front frames are each separated by ms (125-Hz sample rate) and are reconstructed from the data shown in Figs. 13 and 14. The spatial frequencies and the typical time evolution of the reconstructed wave fronts are similar for the laser star and the natural star, although since the data were not obtained simultaneously the specific turbulence pattern that was seen by each was different. The color bar at the bottom shows the calibration of the color scale in units of micrometers of phase delay.

Tables (2)

Tables Icon

Table 1 Properties of the Atmospheric Sodium Layer and the LLNL Site

Tables Icon

Table 2 Contributors to Higher-Order Wave-Front Error of Closed-Loop Laser-Guide-Star Adaptive-Optics Systemsa

Equations (4)

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d N p h / d t ( A rad N / τ n ) [ g u / ( g l + g u ) ] ( A wfs / 4 π z 2 ) f d X ,
d N ph / d t 3.6 × 10 8 f d ( photons / s ) / subaperture .
τ p / τ n ( P L / PRF ) ( σ / h ν ) A s - 1 ( P L / PRF ) ( σ / h ν ) r 0 2 / ( λ z ) 2 ,
ν break 0.7 v wind / d .

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